The present invention relates to thermoelectric power generation in a steam power cycle and a method of generating thermoelectric power in a steam power cycle utilizing latent steam heat.
Steam power plants, including those run by coal, nuclear power, and other fossil fuels, typically generate electricity while achieving a 30-35% overall fuel to power efficiency. A typical steam power plant, described herein as a steam power cycle, includes a steam turbine and a source of steam. In addition, included is a condenser, which serves as an indirect heat exchanger. During operation, steam passes into one section of the heat exchanger. Coolant, typically water, enclosed within metal tubing, separates the condensing steam from the coolant. During the process of condensing the steam, the coolant water is heated in the condenser by the latent heat of the steam and cooled in a cooling tower or other heat sink. The coolant, or water, passes between the condenser, where it absorbs heat, and a cooling tower, where it gives up heat. The condensed steam remains separate from the circulating water and is reheated to provide a source of steam to drive turbines. Therefore, simply stated, high pressure steam is made in a boiler, the pressure and temperature of the steam are reduced in the turbine thereby generating power, and the steam is condensed in the condenser. During the process, the latent heat of condensation is transferred to the cooling water by the condenser and is rejected by the cooling towers. It is estimated that during this process almost 60% of the heat energy from the fuel is lost as latent heat of condensation.
It is proposed to incorporate thermoelectric modules to aid in this conversion of latent heat to power, thereby decreasing the loss of heat during the process, and increasing the efficiency of the power cycle, or power plant. Thermoelectric modules, when serving as power generators, operate by tapping into heat available from a warm body or warm flow and transferring it to a cool body or cool flow. In transferring heat through the thermoelectric modules, electrical power is generated by the Seebeck effect in the material that composes the modules. Typically a thermoelectric device is constructed of an N-type and P-type semiconductor material, such as bismuth telluride. The N-type and P-type semiconductor material are electrically connected in series and thermally connected in parallel. When heat is passed through the material, electricity is generated between the N-type and P-type semiconductor material.
Accordingly, to overcome these problems, it is a purpose of the present invention to provide for a thermoelectric power generator for the capture of latent heat generated by a steam power cycle, thereby increasing the power output of the steam power cycle.
It is another purpose of the present invention to provide for a thermoelectric power generator for the thermoelectric converting of latent steam heat into electricity.
It is yet another purpose of the present invention to provide for a thermoelectric power generator having included as a part thereof thermoelectric modules for the generation of electrical power from latent steam heat.
It is still another purpose of the present invention to provide for a thermoelectric power generator including at least one thermoelectric module mounted to a condenser tube.
It is a still further purpose of the present invention to provide for a method of generating thermoelectric power by thermoelectrically converting latent steam heat into electricity.
It is still a further purpose of the present invention to provide for a method of generating thermoelectric power by converting latent steam heat into electricity utilizing at least one thermoelectric device mounted adjacent a condenser tube.
It is still a further purpose of the present invention to provide for a method of generating thermoelectric power including the use of at least one thermoelectric module that advantageously utilizes heat flux generated within a steam power cycle to generate electricity.
These needs and others are substantially met through provision of a thermoelectric power generator including at least one thermoelectric module mounted adjacent a condenser tube. The thermoelectric module is characterized as utilizing latent heat to increase the power output of a steam power plant. Power, and more particularly, electrical energy generated by the thermoelectric module is added to the total electrical energy generated by the power cycle.
In addition, disclosed is a method of generating thermoelectric power from latent heat produced in a steam power cycle, by mounting at least one thermoelectric module adjacent a condenser tube to produce electrical energy from latent heat.